An aluminum electrolytic capacitor

Abstract

The application relates to an aluminum electrolytic capacitor in the field of capacitors, which comprises a shell and an anode foil, a first layer of electrolytic paper, a cathode foil and a second layer of electrolytic paper arranged in the shell, wherein the anode foil, the first layer of electrolytic paper, the cathode foil and the second layer of electrolytic paper are sequentially arranged and wound to form a core package, the anode foil and the cathode foil are overlapped in the axial direction of the core package, the part of the anode foil overlapped with the cathode foil forms a positive electrode lead-out end, and the part of the cathode foil overlapped with the anode foil forms a negative electrode lead-out end. The aluminum electrolytic capacitor can reduce loss, reduce equivalent series resistance and improve the ripple current performance.

Description

Technical Field

[0001] This application relates to the field of capacitors, and more particularly to an aluminum electrolytic capacitor. Background Technology

[0002] Aluminum electrolytic capacitors are commonly used components in electronic circuits, serving electrical functions such as filtering, bypassing, coupling, decoupling, and phase switching. Due to their large capacitance and low cost, they are widely used in various circuits. An aluminum electrolytic capacitor is made by winding electrolytic paper (with an electrolyte impregnated between an anode foil and a cathode foil coated with a dielectric oxide film) into a core package, which is then sealed in an aluminum shell. Aluminum electrolytic capacitors can be classified into different types, such as leaded, surface-mount, soldered, and screw-terminal types. For example, screw-terminal aluminum electrolytic capacitors have a screw terminal structure, connecting to external circuits via screws for easy installation and fixation. They are typically larger to accommodate a larger electrode area and electrolyte. Current screw-terminal aluminum electrolytic capacitors use aluminum leads welded to a cover plate, but this connection method suffers from high losses, high equivalent series resistance (ESR), and the inability to withstand large ripple currents. Utility Model Content

[0003] In view of the problems existing in the background art, this application provides an aluminum electrolytic capacitor that can reduce the loss of aluminum electrolytic capacitor, reduce the equivalent series resistance and improve the ripple current withstand performance, thereby solving the problems of high loss, large equivalent series resistance and poor ripple current withstand performance of existing aluminum electrolytic capacitors.

[0004] According to one aspect of the present invention, an aluminum electrolytic capacitor is provided, comprising a housing and an anode foil, a first layer of electrolytic paper, a cathode foil, and a second layer of electrolytic paper disposed within the housing. The anode foil, the first layer of electrolytic paper, the cathode foil, and the second layer of electrolytic paper are arranged sequentially from the inside out and wound to form a core package. The anode foil and the cathode foil are staggered and overlapped along the axial direction of the core package. The portion of the anode foil that is staggered relative to the cathode foil forms a positive electrode lead-out end, and the portion of the cathode foil that is staggered relative to the anode foil forms a negative electrode lead-out end.

[0005] In some embodiments of this utility model, the width of the portion of the anode foil offset from the cathode foil and the width of the portion of the cathode foil offset from the anode foil are each independently 0.5cm to 3cm.

[0006] In some embodiments of this utility model, the anode foil is an anode multilayer foil, and the cathode foil is a cathode multilayer foil.

[0007] In some embodiments of this utility model, the widths of the first layer of electrolytic paper and the second layer of electrolytic paper are both smaller than the widths of the anode foil and the cathode foil.

[0008] In some embodiments of this utility model, the lengths of the first layer of electrolytic paper and the second layer of electrolytic paper are both greater than the lengths of the anode foil and the cathode foil.

[0009] In some embodiments of this utility model, the aluminum electrolytic capacitor further includes a negative current collector, a negative terminal cap, and a negative terminal post, wherein the negative lead-out terminal, the negative current collector, the negative terminal cap, and the negative terminal post are connected in sequence.

[0010] In some embodiments of this utility model, the negative terminal post includes a primary negative terminal post connected to the negative terminal cap and a secondary negative terminal post connected to the primary negative terminal post.

[0011] In some embodiments of this utility model, the negative terminal cap, the primary negative terminal post, and the secondary negative terminal post are all provided with a liquid injection port.

[0012] In some embodiments of this utility model, the aluminum electrolytic capacitor further includes a positive current collector, a positive terminal cap, and a positive terminal post, wherein the positive lead-out terminal, the positive current collector, the positive terminal cap, and the positive terminal post are connected in sequence.

[0013] In some embodiments of this utility model, the housing is provided with an explosion-proof port.

[0014] Compared with the prior art, the present invention achieves the following technical effects: The present invention overlaps the anode foil and the cathode foil in a staggered manner, so that the blank parts of the anode foil and the cathode foil are exposed as the positive electrode lead and the negative electrode lead. Compared with the lead strip width of the existing liquid-wound aluminum electrolytic capacitor, the lead width of the present invention is much larger than the former, which greatly reduces the capacitor loss, significantly reduces the equivalent series resistance, and significantly improves the ripple current withstand characteristics. It effectively solves the problems of high loss, large equivalent series resistance, and poor ripple current withstand performance of the existing aluminum electrolytic capacitor. Attached Figure Description

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0016] Figure 1 This is a schematic diagram of the overall structure of the aluminum electrolytic capacitor of this application;

[0017] Figure 2 This is a schematic diagram of the core package structure of this application;

[0018] Figure 3 This is a dimensional schematic diagram of one embodiment of the core package of this application;

[0019] Figure 4These are side views (a) and top views (b) of the negative end cap of this application;

[0020] Figure 5 This is a schematic diagram of the negative current collector structure of this application.

[0021] The labels in the attached diagram represent the following: 1. Core package; 2. Negative electrode lead-out terminal; 3. Negative current collector; 4. Positive electrode lead-out terminal; 5. Positive current collector; 6. Positive electrode post; 7. First-stage negative electrode post; 8. Second-stage negative electrode post; 9. Liquid injection port; 10. Shell; 11. Explosion-proof port; 12. Anode foil; 13. First layer of electrolytic paper; 14. Cathode foil; 15. Second layer of electrolytic paper; 16. Negative electrode cap; 17. Positive electrode cap. Detailed Implementation

[0022] It should be understood that the described embodiments are merely some, not all, of the embodiments in this application. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0023] In the following description, when referring to the accompanying drawings, the same numbers in different drawings denote the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0024] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0025] This utility model discloses an aluminum electrolytic capacitor. For example... Figure 1 and Figure 2As shown, the aluminum electrolytic capacitor includes a housing 10 and an anode foil 12, a first layer of electrolytic paper 13, a cathode foil 14, and a second layer of electrolytic paper 15 installed inside the housing 10. The anode foil 12, the first layer of electrolytic paper 13, the cathode foil 14, and the second layer of electrolytic paper 15 are arranged sequentially from the inside to the outside and wound to form a core package 1. The anode foil 12 and the cathode foil 14 are staggered and overlapped along the axial direction of the core package 1. The portion of the anode foil 12 that is staggered relative to the cathode foil 14 forms the positive electrode lead 4, and the portion of the cathode foil 14 that is staggered relative to the anode foil 12 forms the negative electrode lead 2.

[0026] By using the aluminum electrolytic capacitor in this technical solution, the anode foil 12 and the cathode foil 14 are staggered and overlapped, so that the blank parts of the anode foil 12 and the cathode foil 14 are exposed as capacitance leads, namely the positive lead 4 and the negative lead 2. Compared with the lead strip width of the existing liquid-wound aluminum electrolytic capacitor, the lead width of the present invention is much larger than the former. This greatly reduces the capacitor loss, significantly reduces the equivalent series resistance, and significantly improves the ripple current withstand characteristics, thereby effectively solving the problems of high loss, large equivalent series resistance, and poor ripple current withstand performance of the existing aluminum electrolytic capacitor.

[0027] In some embodiments of this utility model, the width of the portion of the anode foil 12 that is offset from the cathode foil 14 and the width of the portion of the cathode foil 14 that is offset from the anode foil 12 are each independently 0.5cm to 3cm; preferably, the width of the offset portion is 1cm to 3cm.

[0028] When the width of the blank portion has the above dimensions, it serves as a capacitance lead-out terminal, which is beneficial for reducing losses, decreasing the equivalent series resistance, and improving the ripple current withstand characteristics. At the same time, it ensures that the blank portion is not too large and will not have other effects on the overall structure.

[0029] In some embodiments of this utility model, the width of the portion offset between the anode foil 12 and the cathode foil 14, or the width of the portion offset between the cathode foil 14 and the anode foil 12, is not particularly limited. Those skilled in the art can make reasonable choices according to actual needs. For example, the widths can be 0.5cm, 0.7cm, 0.9cm, 1.1cm, 1.3cm, 1.5cm, 1.7cm, 1.9cm, 2.1cm, 2.3cm, 2.5cm, 2.7cm, 2.9cm, 3cm, etc.

[0030] In some embodiments of this utility model, the anode foil 12 is an anode laminated foil, and the cathode foil 14 is a cathode laminated foil.

[0031] In some embodiments of this invention, the anode multilayer foil can be self-made or commercially available multilayer foil. In some embodiments, the thickness of the anode multilayer foil is 140–170 μm, for example, 140 μm, 145 μm, 150 μm, 155 μm, 160 μm, 165 μm, 170 μm, etc. In some embodiments, the specific capacitance of the anode multilayer foil is 0.880–0.890 μF / cm³. 2 For example, a specific volume of 0.880 μF / cm 2 0.882μF / cm 2 0.884μF / cm 2 0.886μF / cm 2 0.888μF / cm 2 0.890μF / cm 2 In some embodiments, the breakdown voltage of the anode multilayer foil is 640V.

[0032] In some embodiments of this invention, the thickness of the cathode multilayer foil can be 15–30 μm, for example, 15 μm, 20 μm, 25 μm, 30 μm, etc. In some embodiments, the specific capacitance of the cathode multilayer foil can be 45–80 μF / cm². 2 For example, a specific volume of 45 μF / cm 2 50μF / cm 2 55μF / cm 2 60μF / cm 2 65μF / cm 2 70μF / cm 2 75μF / cm 2 80μF / cm 2 In some embodiments, the breakdown voltage of the cathode laminate foil is 5V.

[0033] By using appropriate multilayer foils as anode foil 12 and / or cathode foil 14, losses can be further reduced, equivalent series resistance can be decreased, and ripple current withstand characteristics can be improved, thereby enhancing the performance of aluminum electrolytic capacitors.

[0034] In some embodiments of this utility model, the thicknesses of the first electrolytic paper 13 and the second electrolytic paper 15 are 40–70 μm, for example, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, etc., and the densities of the first electrolytic paper 13 and the second electrolytic paper 15 are 0.7–0.8 g / cm³. 3 For example, a density of 0.7 g / cm³ 3 0.75g / cm 3 0.8g / cm 3 wait.

[0035] In some embodiments of this utility model, such as Figure 2 As shown, the widths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 are both smaller than the widths of the anode foil 12 and the cathode foil 14.

[0036] In some embodiments of this utility model, the widths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15, as well as the widths of the anode foil 12 and the cathode foil 14, are not particularly limited. Those skilled in the art can make reasonable selections according to actual needs. As some specific examples, for instance... Figure 3 As shown, when the widths of the anode foil 12 and the cathode foil 14 are 14 cm, and the widths of the offset portions of the anode foil 12 relative to the cathode foil 14 and the cathode foil 14 relative to the anode foil 12 are both 1.5 cm, the widths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 can each be 12.5 cm. In some other embodiments of this application, when the widths of the offset portions of the anode foil 12 relative to the cathode foil 14 and the cathode foil 14 relative to the anode foil 12 are both 1.3 cm, the widths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 can each be 12.7 cm; in some other embodiments of this application, when the widths of the offset portions of the anode foil 12 relative to the cathode foil 14 and the cathode foil 14 relative to the anode foil 12 are both 1.1 cm, the widths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 can each be 12.9 cm. In some other embodiments of this application, when the width of the offset portion of the anode foil 12 relative to the cathode foil 14 and the width of the offset portion of the cathode foil 14 relative to the anode foil 12 are both 0.9 cm, the widths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 can be 13.1 cm respectively; in some other embodiments of this application, when the width of the offset portion of the anode foil 12 relative to the cathode foil 14 and the width of the offset portion of the cathode foil 14 relative to the anode foil 12 are both 0.7 cm, the widths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 can be 13.3 cm respectively.

[0037] Therefore, those skilled in the art can select the required width of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 based on the width of the overlapping portion of the anode foil 12 and the cathode foil 14. When the width of the anode foil 12 and the cathode foil 14 is 14cm, the width of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 is preferably greater than or equal to 11cm and less than 14cm, based on the designed width of the overlapping portion of the anode foil 12 and the cathode foil 14.

[0038] By setting the width of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 to be smaller than the width of the anode foil 12 and the cathode foil 14, the electrolytic paper can separate the overlapping area of ​​the anode foil 12 and the cathode foil 14, and facilitate the shaping of the blank part to form the capacity lead-out terminal.

[0039] In some embodiments of this utility model, such as Figure 2 As shown, the lengths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 are both greater than the lengths of the anode foil 12 and the cathode foil 14.

[0040] In some embodiments of this utility model, the lengths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15, as well as the lengths of the anode foil 12 and the cathode foil 14, are not particularly limited, and those skilled in the art can make reasonable selections according to actual needs.

[0041] Preferably, the lengths of the anode foil 12 and the cathode foil 14 are each independently 700-850 cm, for example, 700 cm, 750 cm, 800 cm, 850 cm, etc., and the lengths of the first layer of electrolytic paper 13 and the second layer of electrolytic paper 15 are each independently 720-870 cm, for example, 720 cm, 770 cm, 808 cm, 820 cm, 870 cm, etc.

[0042] In some embodiments of this utility model, after the anode foil 12, the first layer of electrolytic paper 13, the cathode foil 14 and the second layer of electrolytic paper 15 are wound together, they can be fixed with adhesive tape.

[0043] Preferably, the fixing tape can be polypropylene tape.

[0044] In some embodiments of this utility model, such as Figure 1 and Figure 4 As shown, the aluminum electrolytic capacitor also includes a negative current collector 3, a negative terminal cap 16, and a negative terminal post, with the negative lead 2, negative current collector 3, negative terminal cap 16, and negative terminal post connected in sequence.

[0045] In some embodiments of this utility model, the negative lead-out terminal 2, the negative current collector 3, and the negative end cap 16 can be connected by laser welding.

[0046] In some embodiments of this utility model, the negative terminal post may be located at the center of the negative terminal cap 16.

[0047] Furthermore, the negative terminal post can be pre-molded integrally with the negative terminal cap 16.

[0048] It should be understood that the negative terminal cap 16 closes one end opening of the housing 10, and the negative terminal is located outside the housing 10.

[0049] Furthermore, the negative end cap 16 and the housing 10 can be sealed with an O-ring.

[0050] In some embodiments of this utility model, the negative current collector 3 includes, but is not limited to, aluminum foil, copper foil, lead and its alloys, with aluminum foil being preferred. The structure of the negative current collector 3 is as follows: Figure 5As shown.

[0051] Furthermore, the thickness of the negative current collector 3 is 100–600 μm, for example, thicknesses of 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, etc.

[0052] In some embodiments of this utility model, such as Figure 1 and Figure 4 As shown, the negative terminal includes a primary negative terminal 7 connected to the negative terminal cap 16 and a secondary negative terminal 8 connected to the primary negative terminal 7.

[0053] In some embodiments of this utility model, such as Figure 1 and Figure 4 As shown, the negative terminal cap 16, the primary negative terminal post 7 and the secondary negative terminal post 8 are all provided with a liquid injection port 9. Electrolyte can be injected into the housing 10 through the liquid injection port 9, and the liquid injection port 9 can be sealed after the electrolyte is injected.

[0054] In some embodiments of this utility model, such as Figure 1 As shown, the aluminum electrolytic capacitor also includes a positive current collector 5, a positive terminal cap 17, and a positive terminal 6, with the positive lead 4, positive current collector 5, positive terminal cap 17, and positive terminal 6 connected in sequence.

[0055] In some embodiments of this utility model, the positive lead 4, the positive current collector 5, and the positive end cap 17 can be connected by laser welding.

[0056] Furthermore, the thickness of the positive current collector is 100–600 μm, for example, 100 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, etc.

[0057] In some embodiments of this utility model, the positive terminal post 6 may be located at the center of the positive terminal cover 17, and the positive terminal post 6 may be pre-formed integrally with the positive terminal cover 17.

[0058] It should be understood that the positive terminal cap 17 closes the opening at the other end of the housing 10, and the positive terminal post 6 is located outside the housing 10.

[0059] In some embodiments of this utility model, the positive end cap 17 and the shell 10 may be integrally molded.

[0060] In some embodiments of this utility model, the positive current collector 5 and the positive end cap 17 can be integrally molded.

[0061] In some embodiments of this utility model, the negative end cap 16 and the positive end cap 17 are each independently made of, but are not limited to, aluminum foil, copper foil, lead and their alloys, with aluminum foil being preferred.

[0062] In some embodiments of this utility model, the housing 10 is a metal housing 10, preferably an aluminum housing, and is cylindrical.

[0063] In some embodiments of this utility model, the diameter and height of the aluminum shell are not particularly limited, and those skilled in the art can make reasonable choices according to actual needs.

[0064] For example, in one embodiment of this utility model, the diameter of the aluminum shell is 40-80mm, such as 40mm, 50mm, 60mm, 70mm, 80mm, etc., and the height of the aluminum shell is 120-150mm, such as 120mm, 125mm, 130mm, 135mm, 139mm, 140mm, 145mm, 150mm, etc.

[0065] In some embodiments of this utility model, such as Figure 1 As shown, the housing 10 is provided with an explosion-proof port 11 so that energy can be released in time when the internal pressure of the aluminum electrolytic capacitor rises abnormally, thereby reducing the risk and providing an early warning for timely replacement and maintenance.

[0066] The aluminum electrolytic capacitor in this embodiment of the invention can be prepared by the following method.

[0067] The anode foil 12, cathode foil 14, and electrolytic paper are cut to the designed dimensions, then overlapped in a staggered manner and rolled into a core package 1. The negative electrode of the core package 1 (i.e., the negative electrode lead-out end 2) is then welded to the negative current collector 3. The negative current collector 3 is then welded to the negative terminal cap 16. The core package 1 is placed inside the housing 10, and the core package 1 and the housing 10 are insulated and protected by an insulating ring. Then, the core package is sealed by a roller groove and a second molding seal is applied. The positive electrode of the core package 1 (i.e., the positive electrode lead-out end 4) is welded to the positive current collector 5. The positive terminal cap 17 and the positive current collector 5 are then welded together. Electrolyte is injected, and the injection port 9 is sealed, thus obtaining a fully welded screw terminal type aluminum electrolytic capacitor.

[0068] The present invention will be further described below with reference to specific embodiments.

[0069] Example 1

[0070] Material cutting:

[0071] 1) Cutting of anode foil / cathode foil / electrolytic paper: The thickness of the anode laminated foil used is 155μm, and the specific capacitance is 0.886μF / cm³. 2 The breakdown voltage is 640V. The anode multilayer foil is cut using a foil cutter to a length of 788cm and a width of 14cm according to the design dimensions. The cathode multilayer foil used has a thickness of 20μm and a specific capacitance of 65μF / cm³. 2The breakdown voltage is 5V. The cathode foil is cut using a cutting machine to a length of 788cm and a width of 14cm according to the design dimensions. The electrolytic paper used has a thickness of 60μm and a density of 0.7g / cm³. 3 The electrolytic paper was cut using a cutting machine to a length of 808cm and a width of 12.5cm according to the design dimensions.

[0072] Capacitor assembly:

[0073] 2) Core Bundle: The cut anode foil / cathode foil / electrolytic paper is wound into a core bundle using a winding machine. The stacking order of the anode laminated foil / cathode laminated foil / electrolytic paper is: anode laminated foil, first layer of electrolytic paper, cathode laminated foil, second layer of electrolytic paper. The width of the anode laminated foil is 14cm, the width of the cathode laminated foil is 14cm, the anode laminated foil and cathode laminated foil are staggered by 1.5cm, the overlap width is 12.5cm, the winding needle diameter of the winding machine is Φ8mm, the winding linear speed is 2000mm / s, the tension is controlled at 30N, and the winding alignment is ±0.2mm. The core bundle is wrapped with electrolytic paper and the electrolytic paper is fixed with polypropylene tape.

[0074] 3) Tab shaping: Then, the tabs of the core package are shaped using a core package shaping and flattening machine. (Jig dimensions...) Core package end area: π×29mm×29mm, flattening pressure: 0.3MPa, flattening accuracy: ±0.5mm. The height of a 140mm core package after being pressed down is 133±0.5mm.

[0075] 4) Welding of negative current collector: Then, a laser welding machine is used to weld the core package to the negative current collector, with a negative current collector thickness of 500μm.

[0076] 5) Welding of negative end cap: Then weld the aluminum negative current collector to the aluminum negative end cap.

[0077] 6) Core packaging into the shell: The core is then packaged into the aluminum shell.

[0078] 7) Groove sealing: Use a groove sealing machine to neck and seal the negative electrode.

[0079] 8) Molding and sealing: The negative electrode tip is further squeezed and sealed using a molding machine.

[0080] 9) Positive current collector welding: The core package is welded to the positive current collector using a laser welding machine / s.

[0081] 10) Positive end cap welding: Weld the positive current collector to the positive end cap (the positive end cap and aluminum shell are integrally formed), the thickness of the positive current collector is 500μm.

[0082] 11) Drying: Dry the pre-packaged capacitors in an oven at 85°C for 2 hours.

[0083] 12) Electrolyte injection: Inject electrolyte (70% by mass of ethylene glycol, 25% by mass of ammonium adipate, and 5% by mass of other additives) into the core package through the injection port of the negative terminal cap of the capacitor in the glove box. The injection volume is 120 mL.

[0084] 13) Sealing the injection port: Laser welding is used to seal the injection port.

[0085] Capacitor leak detection / cleaning / sleeving / aging:

[0086] 14) Leak detection: The sealed capacitors are tested for leaks using a high and low temperature test chamber. Temperature range: high temperature: +85℃, low temperature: -40℃, temperature control accuracy: ±0.5℃, number of impact cycles: 5.

[0087] 15) Cleaning: After spraying the sealed capacitor with low pressure (0.2MPa ethanol, 40℃, 3min), dry it with hot air (80℃×15min).

[0088] 16) Sleeve: The aluminum shell of the capacitor is covered with a polyethylene terephthalate (PET) sleeve. The sleeve is made using a sleeve machine and then heated and tightened with a heating gun.

[0089] 17) Aging: The aging process consists of three stages. The first stage involves using a voltage of 1.1 times the rated operating voltage and a current of... The first stage involves constant current boosting, with the ambient temperature at room temperature, for one hour starting from the moment the set voltage is reached and constant. The second stage uses the rated operating voltage for the voltage and the current for... The voltage is boosted using a constant current at an ambient temperature of 85℃ for 4 hours after the set voltage is reached and constant. Third stage: Voltage is taken from the rated operating voltage, and current is taken from... The voltage is boosted by constant current, the ambient temperature is room temperature, and the time is 1 hour from the start of the constant voltage setting (C is the capacitor capacity, V is the rated operating voltage of the capacitor).

[0090] Example 2

[0091] Material cutting:

[0092] The difference from Example 1 is that the electrolytic paper is cut into product foils with a length of 808cm and a width of 12.7cm; otherwise, it is the same as Example 1.

[0093] Capacitor assembly:

[0094] The difference from Example 1 is that the anode foil and cathode foil are staggered by 1.3cm with a gap of 12.7cm, and the overlap width is the same as Example 1.

[0095] Capacitor leak detection / cleaning / sleeving / aging:

[0096] Same as Example 1.

[0097] Example 3

[0098] Material cutting:

[0099] The difference from Example 1 is that the electrolytic paper is cut into product foils with a length of 808cm and a width of 12.9cm; otherwise, it is the same as Example 1.

[0100] Capacitor assembly:

[0101] The difference from Example 1 is that the anode foil and cathode foil are staggered by 1.1 cm, and the width of the overlapping part is 12.9 cm; otherwise, they are the same as Example 1.

[0102] Capacitor leak detection / cleaning / sleeving / aging:

[0103] Same as Example 1.

[0104] Example 4

[0105] Material cutting:

[0106] The difference from Example 1 is that the electrolytic paper is cut into product foils with a length of 808cm and a width of 13.1cm; otherwise, it is the same as Example 1.

[0107] Capacitor assembly:

[0108] The difference from Example 1 is that the anode foil and cathode foil are staggered by 0.9 cm with a gap of 13.1 cm; otherwise, they are the same as in Example 1.

[0109] Capacitor leak detection / cleaning / sleeving / aging:

[0110] Same as Example 1.

[0111] Example 5

[0112] Material cutting:

[0113] The difference from Example 1 is that the electrolytic paper is cut into product foils with a length of 808cm and a width of 13.3cm; otherwise, it is the same as Example 1.

[0114] Capacitor assembly:

[0115] The difference from Example 1 is that the anode foil and cathode foil are staggered by 0.7cm with a gap of 13.3cm; otherwise, they are the same as in Example 1.

[0116] Capacitor leak detection / cleaning / sleeving / aging:

[0117] Same as Example 1.

[0118] Comparative Example 1

[0119] Material cutting:

[0120] 1) Cutting of anode foil / cathode foil / electrolytic paper: The thickness of the anode laminated foil used is 155μm, and the specific capacitance is 0.886μF / cm³. 2 The breakdown voltage is 640V. The anode multilayer foil is cut using a foil cutter to a length of 788cm and a width of 14cm according to the design dimensions. The cathode multilayer foil used has a thickness of 20μm and a specific capacitance of 65μF / cm³. 2 The breakdown voltage is 5V. The cathode foil is cut using a cutting machine to a length of 788cm and a width of 14cm according to the design dimensions. The electrolytic paper used has a thickness of 60μm and a density of 0.7g / cm³. 3 The electrolytic paper is cut using a cutting machine to cut product foils with a length of 808cm and a width of 14cm according to the designed dimensions.

[0121] Capacitor assembly:

[0122] 2) Core Bundle: The cut anode foil / cathode foil / electrolytic paper is wound into a core bundle using a winding machine. The stacking sequence of the anode laminated foil / cathode laminated foil / electrolytic paper is: anode laminated foil, first layer of electrolytic paper, cathode laminated foil, second layer of electrolytic paper. The anode laminated foil / cathode laminated foil / electrolytic paper completely overlap (in the width direction). The winding machine has a needle diameter of Φ8mm, a winding linear speed of 2000mm / s, tension control of 30N, and a winding alignment of ±0.2mm. The core bundle is then wrapped with electrolytic paper and secured with tape.

[0123] 3) Welding of negative electrode lead bar: Weld a negative electrode lead bar to the end of the cathode foil using laser welding. The width of the negative electrode lead bar is 8mm and the length of the negative electrode lead bar is 10mm.

[0124] 4) Welding of negative current collector: Then, a laser welding machine is used to weld the negative electrode lead to the negative current collector, with a thickness of 500μm.

[0125] 5) Core packaging into the shell: The core is then packaged into the aluminum shell.

[0126] 6) Groove sealing: Use a groove sealing machine to neck and seal the negative electrode.

[0127] 7) Molding and sealing: The negative electrode tip is further squeezed and sealed using a molding machine.

[0128] 8) Positive lead bar welding: A positive lead bar is welded to the end of the anode foil using laser welding. The width of the positive lead bar is 8mm and the length of the positive lead bar is 10mm.

[0129] 9) Positive current collector welding: The positive electrode lead is welded to the positive current collector using a laser welding machine.

[0130] 10) Positive end cap welding: Weld the positive current collector to the positive end cap (the positive end cap and aluminum shell are integrally formed), the thickness of the positive current collector is 500μm.

[0131] 11) Drying: Dry the pre-packaged capacitors in an oven at 85°C for 2 hours.

[0132] 12) Electrolyte injection: Inject electrolyte (70% by mass of ethylene glycol, 25% by mass of ammonium adipate, and 5% by mass of other additives) into the core package through the injection port of the negative terminal cap of the capacitor in the glove box. The injection volume is 120 mL.

[0133] 13) Sealing the injection port: Laser welding is used to seal the injection port.

[0134] Capacitor leak detection / cleaning / sleeving / aging:

[0135] Same as Example 1.

[0136] Comparative Example 2

[0137] Material cutting:

[0138] Same as Comparative Example 1.

[0139] Capacitor assembly:

[0140] The difference from Comparative Example 1 is that three positive electrode leads are welded to the anode foil end using laser welding. The three positive electrode leads are at a 120-degree angle to each other. The width of each positive electrode lead is 8 mm and the length of each positive electrode lead is 10 mm. Everything else is the same as Comparative Example 1.

[0141] Capacitor leak detection / cleaning / sleeving / aging:

[0142] Same as Example 1.

[0143] Comparative Example 3

[0144] Material cutting:

[0145] Same as Comparative Example 1.

[0146] Capacitor assembly:

[0147] The difference from Comparative Example 1 is that: five positive electrode leads are welded to the anode foil end using laser welding. The five positive electrode leads are at a 72-degree angle to each other. The width of each positive electrode lead is 8 mm and the length of each positive electrode lead is 10 mm. Everything else is the same as Comparative Example 1.

[0148] Capacitor leak detection / cleaning / sleeving / aging:

[0149] Same as Example 1.

[0150] Comparative Example 4

[0151] Material cutting:

[0152] The difference from Comparative Example 1 is that anodized foil was used as the anode foil, with a thickness of 155 μm and a specific volume of 0.886 μF / cm. 2 The breakdown voltage is 640V; everything else is the same as Comparative Example 1.

[0153] Capacitor assembly:

[0154] Same as Comparative Example 2.

[0155] Capacitor leak detection / cleaning / sleeving / aging:

[0156] Same as Example 1.

[0157] Comparative Example 5

[0158] Material cutting:

[0159] Same as Comparative Example 4.

[0160] Capacitor assembly:

[0161] Same as Comparative Example 3.

[0162] Capacitor leak detection / cleaning / sleeving / aging:

[0163] Same as Example 1.

[0164] Experimental Example

[0165] The basic parameters of the aluminum electrolytic capacitors prepared in Examples 1-5 and Comparative Examples 1-5 were tested, including capacitance, loss, ESR, and ripple current. The capacitance of the aluminum electrolytic capacitors prepared in Examples 1-5 and Comparative Examples 1-5 was 8727 μF.

[0166] (1) Tangent of loss angle (tanδ) test: The Schering bridge method (balanced measurement method) is used. By adjusting the bridge balance, the equivalent impedance of the test sample and the standard capacitor is measured, and the tangent of the dielectric loss angle is calculated. The formula is:

[0167]

[0168] Among them, R c It is the impedance of the capacitor, R. x C is the equivalent series resistance of the test sample. n is the standard capacitance value, and f is the test frequency.

[0169] Operating steps:

[0170] Choose the following connection methods: positive connection (insulation at both ends of the test sample), reverse connection (grounding at one end of the test sample), or diagonal connection (for special scenarios).

[0171] Adjusting the variable resistor R x and variable capacitor C n Balance the bridge and directly read C. n and tanδ.

[0172] The acceptable standard for the loss angle tangent (tanδ) test is: ≤0.06 (120Hz / +20℃).

[0173] (2) Equivalent Series Resistance (ESR) Test Method: An impedance analyzer is used. A sinusoidal AC signal (typically 100Hz to 10kHz) is applied, and the impedance amplitude and phase angle of the capacitor are measured to calculate the ESR value. The formula is:

[0174] ESR=Z 实部 (2)

[0175] Z 实部 This represents the real part of the impedance.

[0176] Operating steps:

[0177] Connect the capacitor to the impedance analyzer and select the test frequency (e.g., 10kHz). Record the impedance-frequency curve and read the real impedance value at the target frequency. Calculate the ESR and verify repeatability (error ≤3%). The pass / fail standard for the equivalent series resistance (ESR) test is: ≤20mΩ (10kHz / +20℃).

[0178] (3) Maximum ripple current test method: The test shall be conducted in accordance with the provisions of IEC 60384.1 4.23.

[0179] Table 1 Test Results

[0180]

[0181] The test results above show that by applying the technical solution of this utility model, the loss of the capacitor can be greatly reduced, the equivalent series resistance can be significantly reduced, and the ripple current withstand characteristic can be significantly improved. This effectively solves the problems of high loss, large equivalent series resistance, and poor ripple current withstand performance of existing aluminum electrolytic capacitors.

[0182] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. An aluminum electrolytic capacitor, characterized in that, The device includes a housing and an anode foil, a first layer of electrolytic paper, a cathode foil, and a second layer of electrolytic paper installed within the housing. The anode foil, the first layer of electrolytic paper, the cathode foil, and the second layer of electrolytic paper are arranged sequentially from the inside out and wound to form a core package. The anode foil and the cathode foil are staggered and overlapped along the axial direction of the core package. The portion of the anode foil that is staggered relative to the cathode foil forms a positive electrode lead-out end, and the portion of the cathode foil that is staggered relative to the anode foil forms a negative electrode lead-out end.

2. The aluminum electrolytic capacitor according to claim 1, characterized in that, The width of the portion of the anode foil offset from the cathode foil and the width of the portion of the cathode foil offset from the anode foil are each independently 0.5cm to 3cm.

3. The aluminum electrolytic capacitor according to claim 1, characterized in that, The anode foil is an anode laminated foil, and the cathode foil is a cathode laminated foil.

4. The aluminum electrolytic capacitor according to claim 1, characterized in that, The widths of the first and second electrolytic paper layers are both smaller than the widths of the anode and cathode foils.

5. The aluminum electrolytic capacitor according to claim 1, characterized in that, The lengths of both the first and second layers of electrolytic paper are greater than the lengths of the anode foil and the cathode foil.

6. The aluminum electrolytic capacitor according to claim 1, characterized in that, It also includes a negative current collector, a negative terminal cap, and a negative terminal post, which are connected in sequence.

7. The aluminum electrolytic capacitor according to claim 6, characterized in that, The negative terminal includes a primary negative terminal connected to the negative terminal cap and a secondary negative terminal connected to the primary negative terminal.

8. The aluminum electrolytic capacitor according to claim 7, characterized in that, The negative terminal cap, the primary negative terminal post, and the secondary negative terminal post are all equipped with liquid injection ports.

9. The aluminum electrolytic capacitor according to claim 1, characterized in that, It also includes a positive current collector, a positive terminal cap, and a positive terminal post, which are connected in sequence.

10. The aluminum electrolytic capacitor according to claim 1, characterized in that, The housing is equipped with an explosion-proof port.

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